Skip to Main Content
Book Chapter

Mag Susceptibility Contrast versus Structure

R. I. Gibson
R. I. Gibson
Search for other works by this author on:
January 01, 1998


Magnetic methods are known to be “nonunique” in their interpretation, but certain generalities are usually true. For example, it is fair to say that most highamplitude magnetic anomalies indicate large contrasts in susceptibility, which in turn indicate large variations in intrabasement rock type. “High amplitude” means anomalies on the order of 150 or 200 nT (gamma) or more. The figure here shows the difference between a simple susceptibility contrast (about a 300-nT anomaly) and a large structure (1219-m, or 4000-ft, fault, producing a 25-nT anomaly). If such features are superimposed on each other, it can be very difficult to separate the effects of structures and susceptibility contrasts. Inasmuch as major intrabasement contacts are often weak zones that may be rejuvenated by later tectonism, this separation is important, even though it may be difficult.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables


Society of Exploration Geophysicists Geophysical References Series

Geologic Applications of Gravity and Magnetics: Case Histories

Richard I. Gibson
Richard I. Gibson
Search for other works by this author on:
Patrick S. Millegan
Patrick S. Millegan
Search for other works by this author on:
Society of Exploration Geophysicists
ISBN electronic:
Publication date:
January 01, 1998




A comprehensive resource of eBooks for researchers in the Earth Sciences

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

View Article Abstract & Purchase Options

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Subscribe Now